We're basing that statement on dimensions. The QX Sport Inspiration Concept rides on a 110.2-inch wheelbase, and is 181.1 inches long, 74.8 inches wide, and 65 inches high. The last QX50, meanwhile, rides on a 113.4-inch wheelbase, and is 186.8 inches long, 71.0 inches wide, and 62.7 inches high. Ignore the different lengths – the concept's front and rear overhangs are remarkably short and aren't likely to translate to production – but the wheelbase, width, and most importantly the height, present a footprint that's remarkably similar to the QX50.
Combine that with our assessment of the QX Sport Inspiration Concept's styling, and it's a virtual certainty that we're looking at the QX50's successor. As we said yesterday, the high beltline, tight greenhouse, long hood, and aggressive headlights are all trademarks of both the QX50 and QX70.
Infiniti didn't say what kind of engine is under this concept car's hood (if there even is one – it might just be an engineless shell), but we're almost certain it's something performance-oriented. That would prove true if and when a new production QX50 is unleashed. We're betting the company will opt for the increasingly familiar setup of the new 3.0-liter, twin-turbocharged V6, a seven-speed automatic transmission, and all-wheel drive, like what you can get on the Q50 Red Sport 400 and new Q60. With 300- and 400-horsepower versions of this engine available, it could signal an introduction of a two-tier QX50 lineup.
We're getting ahead of ourselves, of course. The QX Sport is still only a concept, but Infiniti's latest information dump at the 2016 Beijing Motor Show serves as even stronger evidence that its CUV lineup will grow back to four vehicles sooner rather than later.